Quality assurance for a radiotherapy device

Abstract

A quality assurance method for a radiotherapy device is disclosed. The method comprises disposing a phantom on a patient couch of the radiotherapy device, moving the patient couch to simulate motion of a subject, determining a measured value associated with the phantom, and comparing the measured value to an expected value. A radiotherapy device is also disclosed, the radiotherapy device comprising a radiation source configured to apply a radiation beam, a patient couch, a phantom disposable on the patient couch, and a controller communicatively coupled to the patient couch. A computer-readable medium storing instructions is also disclosed. A phantom for a radiotherapy device is also disclosed.

What is claimed is: 
     
         1 . A quality assurance method for a radiotherapy device, the method comprising:
 disposing a phantom on a patient couch of the radiotherapy device;   moving the patient couch to simulate motion of a subject;   determining a measured value associated with the phantom; and   comparing the measured value to an expected value.   
     
     
         2 . The method according to  claim 1 , comprising:
 delivering a planned radiotherapy treatment to the phantom according to a treatment plan, wherein the measured value comprises a delivered dose to the phantom and the expected value comprises an expected dose from the treatment plan, and wherein the delivering of the planned radiotherapy treatment according to the treatment plan comprises delivering a gated treatment or a tracked treatment.   
     
     
         3 . The method according to  claim 1 , wherein the measured value comprises position data derived from an image of the phantom obtained from a sensor of the radiotherapy device, and the expected value comprises position data derived from a programmed movement of the patient couch. 
     
     
         4 . The method according to  claim 1 , wherein the patient couch is controlled to move to simulate breathing of the subject, comprising at least translating the patient couch along a superior-inferior axis of the radiotherapy device, wherein the superior-inferior axis is parallel or coincident with a longitudinal axis of the patient couch. 
     
     
         5 . The method according to  claim 1 , wherein the patient couch is controlled such that a location of the patient couch along a superior-inferior axis of the radiotherapy device is a sinusoidal function of time, wherein the superior-inferior axis is parallel or coincident with a longitudinal axis of the patient couch. 
     
     
         6 . The method according to  claim 1 , wherein the patient couch is controlled to be at least one of translated along or rotated around multiple degrees of freedom. 
     
     
         7 . The method according to  claim 1 , wherein the phantom comprises an MRMV phantom comprising at least a first material detectable using mega-voltage (MV) imaging and at least a second material detectable using magnetic resonance (MR) imaging. 
     
     
         8 . The method according to  claim 1 , comprising:
 disposing a plurality of phantoms on the patient couch, and, for each respective phantom of the plurality of phantoms, moving the patient couch such that a particular respective phantom is in a predetermined location with respect to the radiotherapy device; and   performing quality assurance using the particular respective phantom in the predetermined location.   
     
     
         9 . The method according to  claim 1 , wherein the phantom comprises a fluid-filled tube containing a ball, the fluid-filled tube being oriented to deviate from a superior-inferior axis of the radiotherapy device along at least a part of a length when the phantom is disposed on the patient couch wherein the superior-inferior axis is parallel or coincident with a longitudinal axis of the patient couch. 
     
     
         10 . The method according to  claim 1 , wherein the moving of the patient couch comprises remotely controlling the patient couch to move as a function of time according to an automated pattern of movement determined in advance of movement of the patient couch. 
     
     
         11 . A radiotherapy device comprising:
 a radiation source configured to apply a radiation beam;   a patient couch;   a phantom disposable on the patient couch; and   controller circuitry communicatively coupled to the patient couch, the controller circuitry configurable to:
 transmit a computer-executable instruction to the patient couch to cause the patient couch to simulate motion of a subject; 
 determine a measured value associated with the phantom; and 
 compare the measured value to an expected value. 
   
     
     
         12 . The radiotherapy device according to  claim 11 , wherein the controller circuitry is configurable to:
 deliver a planned radiotherapy treatment to the phantom according to a treatment plan, wherein the measured value comprises a delivered dose to the phantom and the expected value comprises an expected dose from the treatment plan, and wherein the delivering of the planned radiotherapy treatment according to the treatment plan comprises delivering a gated treatment or a tracked treatment.   
     
     
         13 . The radiotherapy device according to  claim 11 , wherein the measured value comprises position data derived from an image of the phantom obtained from a sensor of the radiotherapy device, and wherein the expected value comprises position data derived from a programmed movement of the patient couch. 
     
     
         14 . The radiotherapy device according to  claim 11 , wherein the computer-executable instruction is configured to cause the patient couch to move to simulate breathing of the subject, comprising at least translating the patient couch along a superior-inferior axis of the radiotherapy device wherein the superior-inferior axis is parallel or coincident with a longitudinal axis of the patient couch. 
     
     
         15 . The radiotherapy device according to  claim 11 , wherein the computer-executable instruction is configured to cause the patient couch to move such that a location of the patient couch along a superior-inferior axis of the radiotherapy device is a sinusoidal function of time wherein the superior-inferior axis is parallel or coincident with a longitudinal axis of the patient couch, and/or wherein the computer-executable instruction is configured to cause the patient couch to at least one of translate along or rotate around multiple degrees of freedom. 
     
     
         16 . The radiotherapy device according to  claim 11 , wherein the phantom comprises an MRMV phantom comprising at least a first material detectable using mega-voltage (MV) imaging and at least a second material detectable using magnetic resonance (MR) imaging. 
     
     
         17 . The radiotherapy device according to  claim 11 , comprising:
 a plurality of phantoms disposable on the patient couch, wherein the controller is configured, for each respective phantom of the plurality of phantoms, to effect movement of the patient couch such that a particular respective phantom is in a predetermined location with respect to the radiotherapy device and wherein the controller circuitry is configurable to perform quality assurance based on the particular respective phantom in the predetermined location.   
     
     
         18 . The radiotherapy device according to  claim 11 , wherein the phantom comprises a fluid-filled tube containing a ball, the fluid-filled tube being oriented to deviate from a superior-inferior axis of the radiotherapy device along at least a part of a length when the phantom is disposed on the patient couch, wherein the superior-inferior axis is parallel or coincident with a longitudinal axis of the patient couch. 
     
     
         19 . The radiotherapy device according to  claim 11 , wherein the controller circuitry is configurable to:
 control the patient couch to move as a function of time according to an automated pattern of movement determined in advance of movement of the patient couch.   
     
     
         20 . A phantom for a radiotherapy device, the phantom comprising:
 a fluid-filled tube containing a ball, the tube being oriented to be non-parallel and non-perpendicular to sides of the phantom along at least a part of a length of the tube.